1. K. Kawasaki, A. Onuki, and T. Ohta, inSystems far from Equilium, L. Garrido, ed. Lecture Notes in Physics, Vol. 132 (Springer Verlag, Berlin, 1980).
2. W. Horsthemke and R. Lefever,Noise Induced Transitions, Synergetic Series, Vol. 15 (Springer Verlag, Berlin, 1983).
3. See the papers by W. Horsthemke, R. Lefever, M. San Miguel, and J. M. Sancho, inStochastic Nonlinear Systems in Physics, Chemistry and Biology, Synergetic Series, Vol. 8 (Springer Verlag, Berlin, 1981).
4. J. M. Sancho and M. San Miguel,Z. Phys. B 36:357 (1980).
5. K. Kitahara, W. Horsthemke, R. Lefever, and Y. Inaba,Progr. Theor. Phys. 64:1233 (1980).